Surgical System and Methods for Mimicked Motion

ABSTRACT

The present invention generally provides methods and devices for controlling movement of an end effector, and in particular for causing mimicked motion between an input tool and an end effector during a surgical procedure. In an exemplary embodiment, a surgical system is provided having a master assembly with an input tool and a slave assembly with an end effector. The master assembly and the slave assembly can be coupled together by a mechanical assembly that is configured to mechanically transfer mimicked, rather than mirrored, motion from the input tool to the end effector. A floating frame is also provided and can be utilized with the surgical system. The floating frame can have a counterbalance that allows the surgical system to “float” above a patient and provide a weightless feel to movement of the surgical system. In addition, the floating frame can provide a number of additional degrees of freedom for ease of movement of the surgical system around the patient and/or the operating room.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. application Ser. No. 12/971,434filed on Dec. 17, 2010 and is a divisional of U.S. application Ser. No.12/971,491 filed on Dec. 17, 2010. The entire teachings of the aboveapplications are incorporated herein by reference

FIELD OF THE INVENTION

The present invention relates to methods and devices for controllingmovement of an end effector assembly on a distal end of a surgicaldevice, and in particular to methods and devices for causing mimickedmotion between a handle and an end effector assembly.

BACKGROUND OF THE INVENTION

Minimally invasive surgical (MIS) instruments are often preferred overtraditional open surgical devices due to the reduced post-operativerecovery time and minimal scarring. Laparoscopic surgery is one type ofMIS procedure in which one or more small incisions are formed in theabdomen and a trocar is inserted through the incision to form a pathwaythat provides access to the abdominal cavity. The trocar is used tointroduce various instruments and tools into the abdominal cavity, aswell as to provide insufflation to elevate the abdominal wall above theorgans. The instruments and tools can be used to engage and/or treattissue in a number of ways to achieve a diagnostic or therapeuticeffect. Endoscopic surgery is another type of MIS procedure in whichelongate flexible shafts are introduced into the body through a naturalorifice.

Conventional MIS devices include a handle, an elongate shaft, and an endeffector at the distal end for effecting tissue. Motion of the endeffector is typically limited to four degrees of freedom (a degree offreedom is the direction in which the end effector can move).Furthermore, motion of the end effector mirrors motion of the handle,such that the operator needs to move the handle in a direction oppositeto the desired direction of movement. Shear forces on MIS instrumentscan also be high, leading to increased operator fatigue.

Various robotic systems have been developed to assist in MIS procedures.Robotic systems can allow for more intuitive hand movements bymaintaining both natural eye-hand axis. Robotic systems can also allowfor more degrees of freedom in movement by including a “wrist” joint onthe instrument, creating a more natural hand-like articulation. Onedrawback with robotic systems, however, is the loss of direct humancontact with the tissue. There can be no true force feedback given tothe surgeon. Another drawback is the high expense to manufacture suchsystems.

Accordingly, there remains a need for improved methods and devices forcontrolling movement of a working end of an endoscopic surgical device,and in particular to methods and devices that utilize a mechanicalconnection to provide for mimicking motion between a handle and an endeffector.

SUMMARY OF THE INVENTION

The present invention generally provides surgical methods and devices inwhich motion of an input tool is mimicked, not mirrored, by motion of anend effector. In one embodiment, a minimally invasive surgical system isprovided and can include an elongate master assembly defining alongitudinal axis and having a tool coupled to a forward end thereof,and an elongate slave assembly defining a longitudinal axis and havingan end effector coupled to a forward end thereof. In some embodiments,the longitudinal axis of the elongate master assembly and thelongitudinal axis of the elongate slave assembly can define a firstplane extending therethrough. The system can further include amechanical coupling system extending between rearward ends of the masterassembly and the slave assembly and being configured to transfercorresponding motion of the tool to the end effector such that the endeffector mimics motion of the tool. In other embodiments, the firstplane can define a first axis parallel to the first plane about whichthe master and slave assemblies can yaw and a second axis transverse tothe first plane. The first axis and the second axis can also define apivot plane transverse to the first plane. When a forward portion of theslave assembly is inserted into a body cavity through an access point ina tissue surface, the pivot plane can extend through the access pointand the tool and the end effector can be positioned forward of the pivotplane.

In some embodiments, when the forward portion of the slave assembly isinserted into a body cavity through an access point in a tissue surface,the mechanical coupling system can be positioned rearward of the pivotplane. In some embodiments, the pivot plane can be perpendicular to thefirst plane. A stabilizing rod can also be coupled between the masterassembly and the slave assembly and can be configured to maintain themaster assembly and the slave assembly offset from one another and in asubstantially parallel orientation.

While there can be many ways of mounting and controlling the master andslave assemblies, in one embodiment, the surgical system can alsoinclude a floating frame coupled to the stabilizing rod and configuredto allow simultaneous movement of the master assembly and the slaveassembly together in parallel with three translational degrees offreedom that include surging, heaving, and swaying while beingrotationally fixed. The floating frame can be coupled to the stabilizingrod through a dual-axis swivel joint that is configured to allowsimultaneous movement of the master assembly and the slave assemblytogether in parallel with two rotational degrees of freedom that includepitching and yawing, while the third rolling rotational degree offreedom can be fixed.

The mechanical coupling system can have many configurations. Forexample, the mechanical coupling system can be configured to transferrotation of the tool about a longitudinal axis of the master assembly tothe end effector to effect mimicked rotation of the end effector about alongitudinal axis of the slave assembly. In addition, the mechanicalcoupling system can be configured to transfer pivoting of the toolrelative to the master assembly to the end effector to effect mimickedpivoting of the end effector relative to the slave assembly. In someembodiments, the mechanical coupling system can also be configured totransfer opening and closing of the tool to the end effector to effectmimicked opening and closing of the end effector.

In general, the mechanical coupling system can include four linkageassemblies. Each linkage assembly can be configured to transfer to theend effector one of rotating the tool relative to the master assembly,pivoting the tool relative to the master assembly, pivoting a firsthandle of the tool, and pivoting a second handle of the tool, to therebyeffect mimicked motion of the end effector. The mechanical couplingsystem can also be configured to scale motion of the tool and transferthe scaled motion to the end effector. In some embodiments, a length ofthe elongate master assembly can be substantially the same as a lengthof the elongate slave assembly.

In another aspect, a minimally invasive surgical system is provided andcan include an elongate master assembly having a forward end with aninput tool coupled thereto, a rearward end, and a longitudinal axisextending between the forward and rearward ends. The surgical system canalso include an elongate slave assembly having a forward end with an endeffector coupled thereto, a rearward end, and a longitudinal axisextending between the forward and rearward ends. The master and slaveassemblies can optionally be oriented substantially in parallel witheach other. The surgical system can further include a mechanical linkageassembly extending between the rearward ends of the master and slaveassemblies such that at least a portion of the linkage assembly isalways perpendicular to the longitudinal axes of the master and slaveassemblies and at least a portion of the linkage assembly is configuredto be at a non-perpendicular angle relative to the longitudinal axes ofthe master and slave assemblies.

The mechanical linkage assembly can have many configurations and can,for example, be configured to transfer rotation of the tool about thelongitudinal axis of the master assembly to the end effector to effectmimicked rotation of the end effector about the longitudinal axis of theslave assembly. The mechanical linkage assembly can also be configuredto transfer pivoting of the end tool relative to the master assembly tothe end effector to effect mimicked pivoting of the end effectorrelative to the slave assembly. Further, the mechanical linkage assemblycan be configured to transfer opening and closing of the tool to the endeffector to effect mimicked opening and closing of the end effector.

In general, the mechanical linkage assembly can include four independentdrive rods, each drive rod being configured to transfer to the endeffector one of rotating the tool relative to the master assembly,pivoting the tool relative to the master assembly, pivoting a firsthandle of the tool, and pivoting a second handle of the tool, to therebyeffect mimicked movement of the end effector. In addition, the surgicalsystem can also include a stabilizing rod coupled between the masterassembly and the slave assembly and configured to maintain the masterassembly and the slave assembly in a substantially parallel orientation.

In some embodiments, the surgical system can include a frame coupled tothe stabilizing rod through a dual-axis swivel joint. The frame can beconfigured to allow simultaneous movement of the master assembly and theslave assembly together in parallel with three translational degrees offreedom. The dual-axis swivel joint can be configured to allowsimultaneous movement of the master assembly and the slave assemblytogether in parallel with two rotational degrees of freedom. The threetranslational degrees of freedom can be surging, heaving, and swaying,and the two rotational degrees of freedom can be pitching and yawing.

In another aspect, a minimally invasive surgical system is provided andcan include a shaft assembly having an end effector disposed on aforward end thereof, the shaft assembly being configured to be insertedthrough an access point in a tissue surface such that the end effectorextends into a body cavity. The system can further include a floatingframe coupled to the shaft assembly by a dual-axis swivel joint. Thefloating frame can be configured to move, when it is anchored to astationary base, with three translational degrees of freedom and thedual-axis swivel joint can be configured to move with two rotationaldegrees of freedom. In some embodiments, when the shaft assembly isdisposed through the access point such that the end effector is disposedwithin the body cavity, the end effector can be configured to bepositioned using one translational degree of freedom from the floatingframe and two rotational degrees of freedom from the dual-axis swiveljoint.

In a further aspect, a method for performing minimally invasive surgeryis provided and can include positioning a slave assembly through asurgical access point in a tissue surface and into a body cavity suchthat an end effector on a forward end of the slave assembly is withinthe body cavity. The end effector can be disposed forward of a pivotplane that extends through the access point and has a first axis that istransverse to a longitudinal axis of the slave assembly and a secondaxis that is perpendicular to the longitudinal axis of the slaveassembly about which the slave assembly yaws. The method can furtherinclude actuating an input tool coupled to a forward end of a masterassembly disposed external to the body cavity to cause mimicked movementof the end effector within the body cavity, the master assemblyextending substantially parallel to the slave assembly and the inputtool being disposed forward of the pivot plane.

In other embodiments, the method can include rotating the input toolabout a longitudinal axis of the master assembly to cause correspondingrotation of the end effector about a longitudinal axis of the slaveassembly, and surging the master assembly to cause mimicked surging ofthe slave assembly through the surgical access point. The method canfurther include moving the master assembly to cause the slave assemblyto pivot about the surgical access point to define a conical volumewithin the body cavity accessible by the end effector.

In one embodiment, positioning a slave assembly through a surgicalaccess point can include moving a frame coupled to both the masterassembly and the slave assembly that allows simultaneous movement of themaster and slave assemblies together in parallel with threetranslational degrees of freedom. The method can further include movinga dual-axis swivel joint coupled between the frame and the master andslave assemblies that allows simultaneous movement of the master andslave assemblies together in parallel with two rotational degrees offreedom. The three translational degrees of freedom can be, for example,surging, heaving, and swaying. The two rotational degrees of freedom canbe, for example, pitching, and yawing. The third rolling rotationaldegree of freedom can be fixed.

In some embodiments, the method can include transferring mimickedmovement of the input tool on the master assembly to the end effector onthe slave assembly through a mechanical linkage. Further, transferringmimicked movement through the mechanical linkage can includetransferring to the end effector rotation of the input tool about alongitudinal axis of the master assembly, as well as pivoting of theinput tool relative to the master assembly. In addition, transferringmimicked movement through the mechanical linkage can includetransferring opening and closing of the input tool to effectsubstantially identical opening and closing of the end effector. In oneembodiment, movement of the end effector can be different in scale thanactuation of the input tool.

In a further aspect, a minimally invasive surgical system is providedand can include a master assembly having a rearward drive system, aforward movable wrist, and a connector extending between the rearwarddrive system and the forward wrist such that movement of an input toolcoupled to the forward wrist is transferred through the cables to causecorresponding movement of the rearward drive system. The surgical systemcan also include a slave assembly having a rearward drive system, aforward movable wrist, and a plurality of cables extending between therearward drive system and the forward wrist such that movement of therearward drive system is transferred through the connector to causecorresponding movement of an end effector coupled to the forward wrist.A mechanical assembly can be directly coupled between the masterrearward drive system and the slave rearward drive system such that themechanical assembly can be configured to transfer motion between themaster and slave rearward drive systems. In some embodiments, the slaveassembly can be configured to be inserted into a body cavity through anaccess point in a tissue surface. The master wrist and the slave wristcan be disposed forward of a plane that extends transverse to alongitudinal axis of the slave assembly and through the access point. Insome embodiments, the master and slave rearward drive systems can eachinclude pulley systems. In addition, the master and slave connectors caneach include a plurality of cables.

The mechanical assembly can have many configurations and can include,for example, four mechanical couplings. The mechanical couplings can becoupled to and move in coordination with the master rearward drivesystem and the slave rearward drive system. Each mechanical coupling canbe configured to transfer from the master assembly to the slave assemblyone of rotating the input tool about a longitudinal axis of the masterassembly, pivoting the input tool relative to a longitudinal axis of themaster assembly, pivoting a first handle of the input tool, and pivotinga second handle of the tool.

In addition, each mechanical coupling can include a superior link, aninferior link, and a middle link, and each link can be coupled togetherby a universal joint. Each mechanical coupling can further include aninferior coupler and a superior coupler, the inferior coupler beingcoupled to the slave pulley system and the superior coupler beingcoupled to the master pulley system. Further, the superior link and theinferior link can each extend along an axis substantially parallelrelative to one another and the middle link can extend along an axistransverse to the axes of the superior and inferior links. The superiorlink, the inferior link, and the middle link can each extend along thesame longitudinal axis. In some embodiments, the surgical system canalso include a stabilizing rod coupled between the master assembly andthe slave assembly and configured to maintain the master assembly andthe slave assembly in an offset and substantially parallel orientation.

In another aspect, a minimally invasive surgical system is provided andcan include a master assembly having an elongate member and defining alongitudinal axis extending between a forward wrist and a rearward drivehousing. The drive housing can have a plurality of drivers disposedtherein, and the forward wrist and the plurality of drivers can beoperatively connected by a drive connector. The system can also includea slave assembly having an elongate member and defining a longitudinalaxis extending between a forward wrist and a rearward drive housing. Thedrive housing can have a plurality of drivers disposed therein, and theforward wrist and the plurality of drivers can be operatively connectedby a drive connector. In some embodiments, the system can furtherinclude a mechanical linkage assembly directly coupled between themaster drive housing and the slave drive housing and can be configuredto transfer mimicked movement of an input tool coupled to the masterwrist to an end effector coupled to the slave wrist. A floating framecan be coupled to the master assembly and the slave assembly and can beconfigured to allow simultaneous movement of the master assembly and theslave assembly together in parallel with three translational degrees offreedom.

In one embodiment, the system can also include a dual-axis swivel jointcoupled between the floating frame and the master and slave assembliesand configured to allow simultaneous movement of the master assembly andthe slave assembly together in parallel with two rotational degrees offreedom. The dual-axis swivel joint can have a first axis of rotationand a second axis of rotation that define a swivel plane. In someembodiments, the forward wrist of the slave assembly and the forwardwrist of the master assembly can be disposed forward of a pivot planethat is parallel with the swivel plane and that extends through anaccess point when the slave assembly is disposed through the accesspoint.

In another embodiment, the three translational degrees of freedom can besurging, heaving, and swaying, and the two rotational degrees of freedomare pitching and yawing, and wherein the third rolling rotational degreeof freedom is fixed. The mechanical linkage assembly can include fourindependently movable drive rods. The master drive housing and the slavedrive housing can each include a pulley housing and the plurality ofmaster drivers and the plurality of slave drivers can each comprise aplurality of movable cables. In some embodiments, the drive rods can becoupled to and move in coordination with the plurality of master pulleysand the plurality of slave pulleys. One of the movable drive rods can beconfigured to transfer to the end effector through the slave cablesrotation of an input tool about a longitudinal axis of the masterassembly received from the master cables. In addition, one of themovable drive rods can be configured to transfer to the end effectorthrough the slave cables pivoting of an input tool relative to themaster assembly received from the master cables. In some embodiments,two of the movable drive rods can be configured to transfer to the endeffector through the slave cables opening and closing of the input toolreceived from the master cables.

In a further aspect, a method for performing minimally invasive surgeryis provided and can include inserting a slave assembly through asurgical access port and into a body cavity such that a slave wrist andan end effector coupled thereto can be disposed within the body cavity.The method can also include manipulating an input tool coupled to amaster wrist of a master assembly to transfer motion through amechanical linkage assembly directly coupled between a master drivesystem and a slave drive system to cause mimicked movement of the endeffector. The master assembly can be disposed outside of the body cavityand can extend parallel to the slave assembly.

In some embodiments, the method can include rotating the input toolabout a longitudinal axis of the master assembly to cause correspondingrotation of the end effector about a longitudinal axis of the slaveassembly. In addition, the master assembly can be surged to causemimicked surging of the slave assembly through the surgical access port.Further, manipulating the input tool can move at least one of aplurality of cables of the master drive system, which can include amaster pulley system.

In another embodiment, inserting a slave assembly through a surgicalaccess port can include moving a frame coupled to both the masterassembly and the slave assembly. Moving the frame can cause simultaneousmovement of the master and slave assemblies together in parallel withthree degrees of translational freedom. The three degrees of freedom canbe surging, heaving, and swaying. In some embodiments, rotating theinput tool on the master assembly about a longitudinal axis of themaster assembly can cause rotation of a first drive rod of themechanical linkage assembly to effect corresponding rotation of the endeffector on the slave assembly. Further, pivoting the input tool on themaster assembly relative to the longitudinal axis of the master assemblycan cause rotation of a second drive rod of the mechanical linkageassembly to effect corresponding pivoting of the end effector of theslave assembly. In some embodiments, opening and closing of the inputtool of the master assembly can rotate third and fourth drive rods ofthe mechanical linkage assembly to effect corresponding opening andclosing of the end effector of the slave assembly. Moving the input toolcan optionally result in scaled movement of the end effector if desired.In general however, a 1:1 ratio between movement of the input tool andmovement of the end effector is maintained regardless of the depth ofpenetration of the end effector within a patient because the input tooland the end effector are of substantially equal distance from the pivotplane.

BRIEF DESCRIPTION OF THE DRAWINGS

The presently disclosed surgical systems and methods will be more fullyunderstood from the following detailed description taken in conjunctionwith the accompanying drawings, in which:

FIG. 1 is a graphical representation of terminology associated with thesix degrees of freedom;

FIG. 2 is a perspective view of one embodiment of a surgical system foraccomplishing mimicked motion coupled to floating frame;

FIG. 3 is a side view of the surgical system of FIG. 2;

FIG. 4A is a perspective view of the surgical system of FIG. 2 in usewith a patient;

FIG. 4B is a perspective view of the surgical system and an exemplaryfloating frame of FIG. 2 illustrating an exemplary swivel plane andpivot plane;

FIG. 5 is a perspective view of exemplary master and slave assemblies ofthe surgical system of FIG. 2;

FIG. 6A is a perspective view of an exemplary wrist and end effectormechanism of the slave assembly of FIG. 5;

FIG. 6B is an exploded view of the wrist and end effector mechanism ofFIG. 6A;

FIG. 7A is a perspective view of one embodiment of a pulley systemassociated with the slave assembly of FIG. 5;

FIG. 7B is an exploded view of the pulley system of FIG. 7A;

FIG. 8A is a cross-sectional view of the slave assembly of FIG. 5showing an exemplary end effector cable system;

FIG. 8B is a perspective view of an exemplary wrist cable system for theslave assembly of FIG. 5;

FIG. 8C is another perspective view of the wrist cable system of FIG.8B;

FIG. 8D is a cross-sectional view of an exemplary slave pulley housingof the slave assembly of FIG. 5 showing a rotational pulley;

FIG. 9A is a perspective view of an exemplary mechanical linkageassembly of the surgical system of FIG. 2;

FIG. 9B is an exploded view of a portion of the mechanical linkageassembly of FIG. 9A;

FIG. 9C is a perspective view of a portion of the mechanical linkageassembly of FIG. 9A;

FIG. 10A is a perspective view of an exemplary coupling assembly thatconnects the surgical system and floating frame of FIG. 2;

FIG. 10B is a perspective view of a dual-axis swivel joint associatedwith the coupling assembly of FIG. 10A;

FIG. 10C is a perspective view of a bearing associated with the couplingassembly of FIG. 10A;

FIG. 10D is a perspective view of the swivel joint of FIG. 10Billustrating an exemplary swivel plane and pivot plane;

FIG. 11A is a perspective view of the floating frame of FIG. 2;

FIG. 11B is a perspective view of a portion of the floating frame ofFIG. 11A;

FIG. 12A is a perspective view of another embodiment of a surgicalsystem for accomplishing mimicked motion;

FIG. 12B is a side view of an exemplary housing of the surgical systemof FIG. 12A showing exemplary slave pulleys and cables; and

FIG. 12C is an opposite side view of the exemplary housing of FIG. 12Bshowing exemplary master pulleys.

DETAILED DESCRIPTION OF THE INVENTION

Certain exemplary embodiments will now be described to provide anoverall understanding of the principles of the structure, function,manufacture, and use of the devices and methods disclosed herein. One ormore examples of these embodiments are illustrated in the accompanyingdrawings. Those skilled in the art will understand that the devices andmethods specifically described herein and illustrated in theaccompanying drawings are non-limiting exemplary embodiments and thatthe scope of the present invention is defined solely by the claims. Thefeatures illustrated or described in connection with one exemplaryembodiment may be combined with the features of other embodiments. Suchmodifications and variations are intended to be included within thescope of the present invention.

The present invention generally provides methods and devices forcontrolling movement of an end effector, and in particular for causingmimicked motion between an input tool and an end effector during asurgical procedure. In an exemplary embodiment, a surgical system isprovided having a master assembly with an input tool and a slaveassembly with an end effector. The master assembly and the slaveassembly can be coupled together by a mechanical assembly that isconfigured to mechanically transfer mimicked, rather than mirrored,motion from the input tool to the end effector. In other words, the endeffector will change direction or orientation in a way that issubstantially identical to the movement of the input tool, although themotion can be different in scale.

In some embodiments, a floating frame can be utilized with the surgicalsystem. The floating frame can have a counterbalance that allows thesurgical system to “float” above a patient and provide a weightless feelto movement of the surgical system. In addition, the floating frame canprovide a number of additional degrees of freedom for ease of movementof the surgical system around the patient and/or the operating room.

TERMINOLOGY

There are a number of ways in which to describe the movement of asurgical system, as well as its position and orientation in space. Oneparticularly convenient convention is to characterize a system in termsof its degrees of freedom. The degrees of freedom of a system are thenumber of independent variables that uniquely identify its pose orconfiguration. The set of Cartesian degrees of freedom is usuallyrepresented by the three translational (position) variables (e.g.,surge, heave, sway) and by the three rotational (orientation) variables(e.g. Euler angles or roll, pitch, yaw) that describe the position andorientation of a component of a surgical system with respect to a givenreference Cartesian frame. As used herein, and as illustrated in FIG. 1,the term surge refers to forward and backward movement, heave refers tomovement up and down, and sway refers to movement left and right. Withregard to the rotational terms, roll refers to tilting side to side,pitch refers to tilting forward and backward, and yaw refers to turningleft and right. In a more general sense, each of the translation termsrefers to movement along one of the three axes in a Cartesian frame, andeach of the rotational terms refers to rotation about one of the threeaxes in a Cartesian frame.

In general, and unless otherwise indicated, the frame of reference forrotational movement will be that of the surgical system itself. Each ofthe rotation axes are perpendicular to each other and remain fixedrelative to the surgical system (i.e., move with the surgical system) sothat the surgical system always has a pitch, roll, and yaw axis aboutwhich the system pitches, rolls, and yaws respectively. The rotationalframe of reference may or may not be aligned with the translationalframe of reference noted below.

In general, and unless otherwise indicated, the frame of reference fortranslational movement will be relative to a fixed portion of thefloating frame. The floating frame can be generally affixed to astationary object such as a hospital bed, an operating table, the floor,the ceiling, etc. Translational movement of the surgical system, as wellas that of the movable portion of the floating frame, will be relativeto this fixed portion and thus generally relative to the bed, floor,ceiling, etc. When translational movement relative to one of the axes inthis reference frame is described, it will be referred to as movementalong the x, y, or z axis. When the translational movement terms areused (i.e., heave, sway, surge), they will generally refer to movementof the surgical system in that particular direction (up/down,right/left, forward/backward) relative to the translational referenceframe. Such movement, however, will not necessarily be along one of thex, y, or z axes.

Although the number of degrees of freedom is at most six, a condition inwhich all the translational and orientational variables areindependently controlled, the number of joint degrees of freedom isgenerally the result of design choices that involve considerations ofthe complexity of the mechanism and the task specifications. Fornon-redundant kinematic chains, the number of independently controlledjoints is equal to the degree of mobility for the end effector. Forredundant kinematic chains, the end effector will have an equal numberof degrees of freedom in Cartesian space that will correspond to acombination of translational and rotational motions. Accordingly, thenumber of joint degrees of freedom can be more than, equal to, or lessthan six.

With regard to characterizing the position of various components of thesurgical system and the floating frame, the terms “forward” and“rearward” will be used. In general, the term “forward” refers to an endof the surgical system that is closest to the end effector and the inputtool, and when in use, generally to the end closer to the patient andthe user. The term “rearward” refers to an end of the surgical systemfarthest from the end effector and the input tool, and when in use,generally to the end farther from the patient and the user.

The terminology used herein is not intended to limit the invention. Forexample, spatially relative terms—such as “superior,” “inferior,”“beneath,” “below,” “lower,” “above,” “upper,” “rearward,” “forward,”and the like—may be used to describe one element's or feature'srelationship to another element or feature as illustrated in thefigures. These spatially relative terms are intended to encompassdifferent positions and orientations of the device in use or operationin addition to the position and orientation shown in the figures. Forexample, if the device in the figures is turned over, elements describedas “inferior to” or “below” other elements or features would then be“superior to” or “above” the other elements or features. Likewise,descriptions of movement along and around various axes includes variousspecial device positions and orientations. As will be appreciated bythose skilled in the art, specification of the presence of statedfeatures, steps, operations, elements, and/or components does notpreclude the presence or addition of one or more other features, steps,operations, elements, components, and/or groups described herein. Inaddition, components described as coupled may be directly coupled, orthey may be indirectly coupled via one or more intermediate components.

There are several general aspects that apply to the various descriptionsbelow. For example, at least one surgical end effector is shown ordescribed in various figures. An end effector is the part of a minimallyinvasive or invasive surgical instrument or assembly that performs aspecific surgical function (e.g., forceps/graspers, needle drivers,scissors, electrocautery hooks, staplers, clip appliers/removers,suction tools, irrigation tools, etc.). Any of these exemplary endeffectors can be utilized with the surgical system described herein.Further, as noted above, an exemplary end effector is manipulated by aninput tool. The input tool can be any tool that allows successfulmanipulation of the end effector, whether it be a tool similar in shapeand style to the end effector, or a tool that is different in shape andstyle to the end effector. In general, the input tool can be larger thanthe end effector to facilitate ease of use. For example, the input toolcan have finger loops or grips of a size suitable for a user to hold, asshown by the input tool disclosed herein. However, the end effector andthe input tool can have any relative size.

As noted briefly above, the slave assembly of the surgical system can bepositioned inside a patient's body cavity through an access point in atissue surface for minimally invasive surgical procedures. Typicallycannulas are used to provide a pathway through a tissue surface and toprevent a surgical instrument or guide tube from rubbing on patienttissue. Cannulas can be used for both incisions and natural orifices.Some surgical procedures require insufflation, and the cannula caninclude one or more seals to prevent excess insufflation gas leakagepast the instrument or guide tube. In some embodiments, the cannula canhave a housing coupled thereto with two or more sealed ports forreceiving various types of instruments besides the slave assembly. Itwill be appreciated by those skilled in the art that any of the surgicalsystem components disclosed herein can have a functional seal disposedthereon, therein, and/or therearound to prevent and/or reduceinsufflation leakage while any portion of the surgical system isdisposed through a surgical access port, such as the cannula notedabove. The surgical system can also be used in open surgical procedures.As used herein, a surgical access point is a point at which the slaveassembly enters a body cavity through a tissue surface, whether througha cannula in a minimally invasive procedure or through an incision in anopen procedure.

Surgical System Generally

One exemplary embodiment of a surgical system 10 is illustrated in FIG.3. The surgical system 10 can include four main components. First, amaster assembly 200 is provided for inputting user directed movement tothe surgical system 10. Second, a slave assembly 100 is provided foroutputting mimicked movement received from the master assembly 200.Third, a mechanical linkage assembly 300 couples the master assembly 200and the slave assembly 100 and mechanically transfers movement from themaster assembly 200 to the slave assembly 100. Finally, a couplingassembly 400 is provided for maintaining the relative orientation of themaster assembly 200 and the slave assembly 100 and for coupling thesurgical system 10 to a frame, for example a floating frame 500illustrated in FIG. 2.

The relative positioning of the various components of the surgicalsystem 10 can be important for the transfer of mimicked, rather thanmirrored, motion. As shown in FIGS. 3 and 5, in some embodiments, themaster assembly 200 can be generally elongate with an input tool 202disposed on a forward end 204 thereof. Similarly, the slave assembly 100can be generally elongate with an end effector 102 disposed on a forwardend 104 thereof. As shown in FIG. 3, the master assembly 200 and theslave assembly 100 can be oriented substantially parallel to oneanother. The mechanical linkage assembly 400 can extend between themaster assembly 200 and the slave assembly 100 and can generally beoriented perpendicularly thereto, although certain portions of themechanical linkage assembly 400 can extend non-perpendicularly to theassemblies 100, 200 as will be described below. The coupling assembly500 can also extend generally perpendicularly to the master assembly 200and the slave assembly 100 and generally in parallel with the mechanicallinkage assembly 400. The coupling assembly 500 can maintain theparallel orientation of the master assembly 200 and the slave assembly100. A person skilled in the art will appreciate that the orientation ofthe various components are exemplary in nature and that the componentscan be oriented at various angles relative to one another if desired.

In use, the positioning and orientation of the four major components ofthe surgical system 10 as described above results in the transfer ofmimicked motion between the input tool 202 and the end effector 102. Asshown in FIG. 4A, the input tool 202 and the end effector 102 (notshown), and thus a user and the patient H, are on the same forward endof the surgical system 10. When the end effector 102 of the slaveassembly 100 is disposed within a body cavity during use as shown inFIG. 4, the slave assembly 100 can extend through a surgical accesspoint A in a tissue surface such that the surgical system 10 can pivotabout this access point A. Both the end effector 102 and the input tool202 are positioned forward of a pivot plane P that extends through theaccess point A. As shown in FIG. 4A, the pivot plane P can have a firstaxis F.A. that is parallel with a first plane F defined by thelongitudinal axes of the slave assembly 100 and the master assembly 200and about which the surgical system 10 yaws. The pivot plane P can alsohave a second axis S.A. that is transverse to the first plane F suchthat the pivot plane P extends transverse to the first plane F.Additional details of the pivot plane P will be described in more detailbelow with regard to FIGS. 10B and 10D. Because of this configuration,the master assembly 200 and the slave assembly 100 are capable ofmimicked motion. For example, when a user changes the pitch of themaster assembly 200 downward, the slave assembly 100 identically pitchesdownward. If the input tool 202 were instead on the rearward side of thepivot plane P while the end effector 102 remained on the forward side,the pitch change would be mirrored, rather than mimicked, and the endeffector 102 would pitch upward when the input tool 202 was pitcheddownward. Similarly, if a user changes the yaw of the master assembly200 rightward, the slave assembly 100 identically yaws rightward.However if the input tool 202 were on the rearward side of the pivotplane P, the end effector 102 would yaw leftward in response to theinput tool 202 yawing rightward. The mimicked movement of the surgicalsystem 10 provides a more natural way for a user to perform surgicalprocedures since a user's movements are transferred to the end effector102 identically.

Surgical System Detail

The master assembly 200 and the slave assembly 100 of the surgicalsystem 10 are shown in more detail in FIG. 5. In some embodiments, theslave assembly 100 can include a slave arm 106 extending between aforward wrist 108 and a rearward drive housing, such as a rearwardpulley housing 110, while the master assembly 200 can include a masterarm 206 extending between a forward wrist 208 and a rearward drivehousing such as a rearward pulley housing 210. The slave assembly 100and the master assembly 200 can each have a size that is substantiallythe same, and thus the arms 106, 206 can have a length that issubstantially the same. A connector system, such as a plurality ofcables described in detail later, can extend through the elongate arms106, 206 between the wrists 108, 208 and the pulley housings 110, 210and can be configured to communicate movement at the wrists 108, 208 todrivers, such as pulleys disposed within the pulley housings 110, 210.The drivers and/or pulleys in the pulley housings 110, 210 can generallybe configured to output and/or receive movement to/from the mechanicallinkage system 300 coupled thereto. As will be appreciated by thoseskilled in the art, the pulley housing, pulleys, and cable systemsdescribed herein can generally be replaced by any mechanical drivesystem known in the art, such as a gear system or other mechanism. Forexample, the pulley housings 110, 210 can be replaced by drive housings,the pulleys can be replaced by drivers, and the pulley cables can bereplaced by any connectors known in the art, such as rack and pinions,gears, and/or belts.

The master assembly 200 and the slave assembly 100 can be substantiallyidentical in structure apart from the input tool 202 and the endeffector 102. Thus only one assembly need be described in detail. Theslave assembly 100 will thus be described in detail with referencenumbers in the 100s. An identical and corresponding component in themaster assembly 200 will have a reference number in the 200s, with thelast two digits being identical to the corresponding slave assemblyreference number. For example, the slave wrist has a reference number“108” while the master wrist has a reference number “208.” Thisconvention will be followed throughout the description.

The arm 106 and the wrist 108 of the slave assembly 100 are shown inmore detail in FIGS. 6A-7A. In some embodiments, the arm 106 of theslave assembly 100 can be a substantially rigid elongate member with abore 107 extending therethrough and having a length substantiallygreater than a diameter thereof. The arm 106 can define a centrallongitudinal axis L.S. extending between the forward end 104 and arearward end 112 thereof. In some embodiments, the rearward end 112 ofthe arm 106 can extend into and terminate within the pulley housing 110.The opposite, forward end 104 of the arm 106 can couple to the wrist 108through the use of a clevis joint, as shown in FIGS. 6A and 6B. Inparticular, the forward end 104 of the arm 106 can have two extensionportions 114 a, 114 b that form a clevis for receiving the wrist 108.Each extension portion 114 a, 114 b can have an opening 115 a, 115 bformed laterally therethrough for receiving a clevis pin 116.

As noted above, the forward wrist 108 can be coupled between the forwardend 104 of the arm 106 and the end effector 102. The wrist 108 can takemany forms suitable for coupling the arm 106 and the end effector 102,and in the illustrated embodiment it can generally include a frame 118coupled to a plurality of pulleys for communicating movement of the endeffector 102 to pulleys within the pulley housing 110. The wrist frame118 can have, for example, a tang 120 formed at its rearward end with anopening 122 formed laterally therethrough that can be aligned with theopenings 115 a, 115 b formed in the extension portions 114 a, 114 b forreceiving the clevis pin 116. The coupling between the wrist tang 118and the extension portions 114 a, 114 b can allow the wrist 108 torotate about the clevis pin 116, thereby allowing the wrist 108 and theend effector 102 to pitch (i.e., to pivot) relative to the arm, as shownby arrow A in FIG. 8B.

The wrist 108 can include any number of pulleys to accomplish desiredmotion. Two of the plurality of pulleys within the wrist 108 can bepositioned within the clevis joint adjacent to the tang 120 of the wristframe 118. In particular, one pulley 124 a can be positioned between thetang 120 and the extension portion 114 a, and another pulley 124 b canbe positioned between the tang 120 and the opposite extension portion114 b. The pulleys 124 a, 124 b can have corresponding openings 126 a,126 b formed therethrough for receiving the clevis pin 116 that extendsthrough the tang 120 and the extension portions 114 a, 114 b. Thepulleys 124 a, 124 b can each receive a cable 128 a, 128 b thattransfers pitching motion to the wrist 108, i.e., when the pulleys 124a, 124 b are rotated by the cables 128 a, 128 b in a first direction,the wrist 108 and the end effector 102 pitch in the same firstdirection.

The wrist frame 118 can also have two extension portions 130 c, 130 dextending forwardly from the tang 120 and forming another clevis jointat its forward end for coupling to the end effector 102. Each of theextension portions 130 c, 130 d can have an opening 132 c, 132 d formedlaterally therethrough in a direction perpendicular to the lateralopening 122 formed in the tang 118 for receiving the clevis pin 116. Inthe illustrated embodiment, the end effector 102 has opposed jaws 134,136 configured to open and close relative to one another and each havinga plurality of gripping teeth 138 formed thereon. Each jaw member 134,136 can have a tang 140, 142 formed on a rearward end thereof with alateral opening 144, 146 formed therethrough for receiving the clevispin 148. In the illustrated embodiment, each tang 140, 142 can alsoinclude a pulley 150, 152 rigidly disposed thereon for receiving acorresponding cable 154, 156 to communicate movement to each jaw member134, 136.

When assembled, the tangs 140, 142 of the jaw members 134, 136 can bepositioned adjacent to each other between the extension portions 130 c,130 d of the wrist frame 118 such that the two pulleys 150, 152 arepositioned in contact with one another. Due to each pulley 150, 152receiving independently movable cables 154, 156, each jaw member 134,136 can be configured to rotate about the clevis pin 148 independentlyof the other jaw member 136, 134 such that each yaws relative to the endeffector 102 and the arm 106. In other words, since the end effector 102is configured to pitch relative to the arm 106, and since the jawmembers 134, 136 each pivot in a direction opposite to the directionthat the end effector 102 pitches, the jaw members 134, 136 can beconsidered to yaw relative to the arm 106 and relative to the endeffector 102. The wrist 108 can include two additional pulleys 158, 160disposed on opposite sides thereof and oriented in the same direction asthe wrist pulleys 124 a, 124 b and in the opposite direction to the jawmember pulleys 150, 152. The pulleys 158, 160 can receive the cables154, 156 from the jaw member pulleys 150, 152 and can orient the cables154, 156 in the same direction as the wrist cables 128 a, 128 b toextend through the tubular arm 106.

Surgical System Pulley Housing

As noted above, the rearward end 112 of the arm 106 can extend into thepulley housing 110 that generally holds a plurality of rearward pulleys.In the illustrated embodiment shown in FIGS. 7A and 7B, there are fourrearward pulleys 166 a, 166 b, 166 c, 166 d (jointly “166”) that receivethe cables 128 a, 128 b, 154, 156 from the wrist 108 and a cable 186from the arm 106 (shown in FIG. 8C and described below) and transfermovement to and/or from the mechanical linkage assembly 300.

The pulley housing 110 can take many forms, but in the illustratedembodiment, the pulley housing 110 is in the form of a substantiallyrectangular box with a housing cover 162 and a housing base 164 thatcouple together to enclose the rearward end 112 of the arm 106 and thepulleys 166. The housing cover 162 and the housing base 164 can becoupled together by any mechanism known in the art including, but notlimited to, a press fit, interference fit, fasteners, adhesives, etc.The housing cover 162 can include an opening 168 formed in a forwardsidewall 170 thereof for receiving the arm 106 therethrough whileallowing rotation of the arm 106 relative thereto.

The housing base 164 can generally be configured to seat and retain thepulleys 166. Thus, the housing base 164 can include a slotted brace 172for seating a rearward flange 174 of the arm 106. The housing base 164can also include four openings 176 a, 176 b, 176 c, 176 d (jointly“176”) extending therethrough for seating the four pulleys 166. Fourconnector plates 180 a, 180 b, 180 c, 180 d (“jointly “180”) can seatthe pulleys 166 within the openings 176. Each connector plate 180 canhave a base 182 a, 182 b, 182 c, 182 d (jointly “182”) with a spool rod184 a, 184 b, 184 c, 184 d (jointly “184”) extending perpendicularlytherefrom for seating the pulleys 166. The pulleys 166 can be fixedlyand/or rigidly coupled to their corresponding connector plates 180 sothat neither the pulleys 166 nor the plates 180 are capable of rotationrelative to each other. A support wall 178 can extend upward from thehousing base 164 between the pulleys 166 for separating the cables 154,156 for the rearward pulleys 166 c, 166 d from the cables 128 a, 128 b,186 for the forward pulleys 166 a, 166 b and for guiding the cables 128a, 128 c, and 128 d into the arm 106.

Each of the four pulleys 166 in the pulley housing 110 can be configuredto transfer a specific type of movement to and/or from the mechanicallinkage assembly 300. Thus, as shown in FIGS. 8A-8C, in general, thecables 128 a, 128 b, 154, 156 for transferring movement to and from thewrist 108 can extend from the pulleys 124 a, 124 b, 150, 152,respectively, at the wrist 108 to three of the pulleys 166 a, 166 c, 166d in the pulley housing 110 (cables 128 a, 128 b both extend to pulley166 a). For example, as shown in FIG. 8C, the cables 128 a, 128 bextending from each of the wrist pulleys 124 a, 124 b can extend throughthe arm 106 to the pulley 166 a such that pitching of the wrist 108(shown by arrow A in FIG. 8B) results in rotation of the pulley 166 a.In addition, as shown in FIG. 8A, the cable 154 can extend between thejaw member pulley 150 and the pulley 166 d in the housing 110. Likewise,the cable 156 can extend between the other jaw member pulley 152 and thepulley 166 c in the housing 110. Each of the cables 154, 156 can bepulled by rotation of their corresponding pulley 166 d, 166 c to causeyawing movement of the jaws 134, 136 as shown by arrows B and C.

The fourth pulley 166 b in the pulley housing 110, shown in FIG. 8D, canreceive the cable 186 from a rotational pulley 188 disposed on therearward end 112 of the arm 106. The rotational pulley 188 can have acentral axis C.A. that is co-linear with the central longitudinal axisof the arm L.S. The cable 186 can extend from the rotational pulley 188to the pulley 166 b such that as the arm 106 rotates as indicated byarrow D, the cable 186 functions to rotate the corresponding fourthpulley 166 b in a corresponding direction D′.

As noted above, each of the four pulleys 166 within the housing 110 canbe rigidly coupled to the connector plates 180 that extend through thehousing base 164. This allows the pulleys 166 to be coupled to themechanical linkage assembly 300 through their corresponding connectorplates 180 as shown in FIG. 9A and as will be described in more detailbelow. In this way, rotation of the pulleys 166 results in correspondingrotation of the mechanical linkage assembly 300 and vice versa, as willalso be described in detail below.

As noted above, the master assembly 200 is substantially identical tothe above-described slave assembly 100 except that the input tool 202 iscoupled to the forward wrist 204 rather than the end effector 102. Itwill be appreciated by those having ordinary skill in the art that theabove-described arm/wrist/pulley system is only exemplary in nature.There are a number of robotic arms that can be used as a master/slaveassembly, and there are a number of additional joints and/or wrists thatcan be included on a particular arm to provide jointed movement of thearm. Non-limiting examples of such components can be found in U.S. Pat.No. 5,702,408 Wales et al., incorporated by reference in theirentireties.

Surgical System Mechanical Linkage Assembly

The mechanical linkage assembly 300 is illustrated in more detail inFIGS. 9A-9C, and as with the wrist/arm/pulley system described above,detailed views of the slave assembly 100 are shown. The coupling betweenthe mechanical linkage assembly 300 and the master assembly 200 can beidentical to that of the slave assembly 100 and thus need not be shownor described in detail.

As shown in FIG. 9A, the mechanical linkage assembly 300 can generallyextend between the master pulley housing 210 and the slave pulleyhousing 110 and can transfer motion therebetween. In some embodiments,the mechanical linkage assembly 300 can include four drive rods 302 a,302 b, 302 c, 302 d (jointly “302”) that correspond with the fourpulleys 166, 266 in each of the housings 110, 210. Each drive rod 302can be coupled to one of the pulleys 266 in the master pulley housing210 and one of the pulleys 166 in the slave pulley housing 110. Inaddition, each drive rod 302 can rotate in response to and/or to causerotation of each of the pulleys 166, 266. In this way, movement iscommunicated between the master assembly 200 and the slave assembly 100.

While the drive rods 302 can have any configuration suitable fortransferring rotational motion, in the illustrated embodiment, eachdrive rod 302 includes a series of linkages and a coupling mechanismthat can provide a secure mating between the linkages and the connectorplates 180, 280 of the pulleys 166, 266. For example, as shown in FIG.9A, the drive rods 302 can include corresponding superior couplers 304a, 304 b, 304 c, 304 d (jointly “304”) that connect with the connectorplates 280 of the master pulleys 266. The drive rods 302 can alsoinclude inferior coupler 306 a, 306 b, 306 c, 306 d (jointly “306”) thatconnect with corresponding connector plates 180 of the slave pulleys166. The couplers 304, 306 can have any size and shape as needed, but inthe illustrated embodiment they are substantially disk-shaped membersthat are of the same size as the connector plates 180, 280. Referring toFIG. 9B which shows the coupling to the slave assembly 100, there aremany ways in which to mate the couplers 306 to the connector plates 180.In the illustrated embodiment, the connector plates 180 each have twonubs 181 extending therefrom that are received by the couplers 306 andsecured by fasteners 308. This connection ensures that the connectorplates 180 and their corresponding couplers 306 rotate at the same rate,and do not rotate relative to one another.

Referring back to FIG. 9A, the coupling mechanism can also includesuperior receiving members 310 a, 310 b, 310 c, 310 d (jointly “310”)that can extend perpendicularly from the superior couplers 304, as wellas inferior receiving members 312 a, 312 b, 312 c, 312 d (jointly “312”)that can extend perpendicularly from the inferior couplers 306. Eachreceiving member 310, 312 can be a tubular member having a diameter lessthan that of the coupler 306 and that is configured to receive a linkageof the corresponding drive rod 302 therein. In some embodiments, thereceiving members 310, 312 can be integrally formed with the superiorand inferior couplers 304, 306 and/or can be coupled thereto by anymechanism known in the art such that they are rigidly coupled togetherand thus incapable of rotation relative to each other.

The superior receiving member 310 can be configured to receive andsecure a superior linkage 314 a, 314 b, 314 c, 314 d (jointly “314”) ofa particular drive rod 302 therein. The superior linkages 314 can havean outer diameter less than an inner diameter of the receiving members310 so that a superior portion of the superior linkages 314 can fitinside the receiving member 310. Likewise, the inferior receivingmembers 312 can each receive an inferior linkage 316 a, 316 b, 316 c,316 d (jointly, “316”) of the corresponding drive rod 302 therein. Abolt or other fastening mechanism can extend laterally through eachlinkage 314, 316 and its corresponding receiving member 310, 312 tosecure the two together and to prevent the linkages 314, 316 fromrotating relative to the receiving members 310, 312. The superior andinferior linkages 314, 316 can therefore remain substantiallyperpendicular to the superior and inferior couplers 304, 306, as well asto the longitudinal axes of the master arm 206 and the slave arm 106.

On an end of the linkages 314, 316 opposite to that held within thereceiving members 310, 312, each of the superior and inferior linkages314, 316 can couple to a middle linkage 318 a, 318 b, 318 c, 318 d(jointly “318”) of the drive rods 302 such that the middle linkages 318connect with the superior and inferior linkages 314, 316. The couplingbetween the middle linkages 318 and the superior and inferior linkages314, 316 can be any sort of joint known in the art that allows pivotingof the linkages 314, 316, 318 in different directions, but preferablylimits pivoting of the linkages 314, 316, 318 to one dimension. Thisallows the parallel orientation of the master and slave assemblies 200,100 to be maintained while also allowing the entire drive rod 302 to berotated as a unit. For example, as shown in FIGS. 9B and 9C, thecoupling between the linkages 314, 316, 318 can be universal joints 320a, 320 b, 320 c, 320 d (jointly “320”) that allow each of the linkages314, 316, 318 to pivot in one direction only, while allowing eachlinkage 314, 316, 318 to pivot in a direction different than the otherlinkages 314, 316, 318. A universal joint is particularly useful fortransferring rotational motion, however any suitable joint can be used.The middle linkages 318 can generally have a length that issubstantially greater than a length of the superior and inferiorlinkages 314, 316, while the superior and inferior linkages 314, 316 canhave substantially the same length. As will be appreciated by those ofordinary skill in the art, the linkages 314, 316, 318 can have anylength desired. In some embodiments, the superior, inferior, and middlelinkages 314, 316, 318 can all have the same diameter, although they canoptionally have different diameters if desired.

It is to be appreciated that in general, a 1:1 ratio between movement ofthe input tool 202 and movement of the end effector 102 is maintainedregardless of the depth of penetration of the end effector 102 within apatient because the input tool 202 and the end effector 102 are ofsubstantially equal distance from the pivot plane P. In some embodimentshowever, the mechanical linkage assembly 300 can include features thatallow scaled motion between the input tool 202 and the end effector 102.For example, if the diameters of the pulleys 166, 266 are equal, thenthe ratio of input to output is 1 to 1. If the diameter of the pulley266 is double that of the diameter of the pulley 166, then the ratio ofthe input to output is 2 to 1 such that the size of motion inputted intothe system through the master assembly 200 will result in motion scaledby half in the slave assembly 100. A person skilled in the art willappreciate the variations and possibilities of scaled motion between themaster assembly 200 and the slave assembly 100.

In use, mimicked movement can be transferred from the input tool 202 tothe end effector 102. For example, if the input tool 202 on the masterassembly 200 is pivoted or pitched in a first direction relative to thearm 206, the two cables 228 a, 228 b disposed around the wrist pulleys224 a, 224 b are pulled in the first direction. The two cables 228 a,228 b extend through the master arm 206 and around the pulley 266 a inthe master pulley housing 210, and thus cause the pulley 266 a to alsorotate in the first direction. Since there can be a rigid couplingbetween the pulley 266 a and its drive rod 302 a, the drive rod 302 a isalso rotated in the first direction. There can also be a rigid couplingbetween the drive rod 302 a and the pulley 166 a in the slave pulleyhousing 110. The pulley 166 a in the slave pulley housing 110 istherefore rotated, thereby pulling on the two cables 128 a, 128 b thatextend through the slave arm 106 to the corresponding pulleys 124 a, 124b in the slave wrist 108. The two cables 128 a, 128 b rotate each of thetwo wrist pulleys 124 a, 124 b in the first direction, thereby causingthe end effector 102 to also pivot or pitch in the first direction. Inthis way, mimicked motion is transferred from the input tool 202 to theend effector 102. Similar mechanics apply to the other three types ofmovement: rotation of the master arm 206 about its longitudinal axis torotate the slave arm 206 about its longitudinal axis, and pivoting ofeach of the jaw members 234, 236 relative to the input tool 202 and thearm 206 to cause pivoting of the jaw members 134, 136 relative to theend effector 202 and the arm 106.

Surgical System Coupling Assembly

As shown in FIG. 3, the coupling assembly 400 can generally maintainparallel alignment between the master assembly 200 and the slaveassembly 100. It can also couple the master and slave assemblies 200,100 to the floating frame 500. Referring to FIGS. 10A and 10B, thecoupling assembly 400 can therefore include a stabilization member 402that extends between the master and the slave assemblies 200, 100 tomaintain their alignment, and a dual-axis swivel joint 404 that can becoupled between the stabilization member 402 and the floating frame 500to couple the two together.

While the stabilization member 402 can have many configurations, in theillustrated embodiment, the stabilization member 402 can include threelinkages 406, 408, 410 coupled between a master bearing 412 and a slavebearing 414 that receive the master and slave arms 206, 106,respectively. The master and the slave bearings 412, 414 can function tocouple the linkages 406, 408, 410 of the stabilization member 402 to themaster and the slave arms 206, 106. While the bearings 412, 414 can bepositioned anywhere along the master and the slave arms 206, 106, toavoid interference of the stabilization links 406, 408, 410 with tissueduring insertion of the slave arm 106 into a body cavity, in theillustrated embodiment they are positioned just forward of the pulleyhousings 210, 110. The bearings 412, 414 can be, for example, ballbearings, the details of which are shown in more detail in FIG. 10C.Each of the bearings 412, 414 can have an opening 416, 418 formedtherethrough with a bearing surface (not shown) and ball bearings 420disposed therein. The master and the slave arms 206, 106 can extendthrough each of their respective bearings 412, 414 and can rotaterelative to the bearings 412, 414 against the bearing surface. In thisway, rotation of the master and the slave arms 206, 106 is not impinged.

The three linkages 406, 408, 410 of the stabilization member 402 canextend between the master bearing 412 and the slave bearing 414. Inparticular, the superior stabilization linkage 410 can extendsubstantially perpendicularly from the master bearing 412, and theinferior stabilization linkage 406 can extend substantiallyperpendicularly from the slave bearing 414. In some embodiments, thesuperior and inferior stabilization linkages 410, 406 can be integrallyand/or unitarily formed with the master and the slave bearings 412, 414,respectively, such that they are rigidly and fixedly disposed relativethereto. In other embodiments, they can be coupled together by anymechanism known in the art, including fixation members, joints, etc. Themiddle stabilization linkage 408 can connect the superior linkage 410and the inferior linkage 406. The three linkages 406, 408, 410 cancouple together by way of, for example, a clevis style joint and/orhinge style joint, allowing pivoting of the linkages 406, 408, 410relative to one another in one dimension. For example, the linkage 406can be coupled to the linkage 408 by a pivot joint 404 b, and thelinkage 410 can be coupled to the linkage 408 by a pivot joint 404 a.This allows the master assembly 200 and the slave assembly 100 to surgeslightly relative to one another to maintain their parallel orientationduring manipulation of the assembly 10, while fixing all rotationaldegrees of freedom relative to one another. For example, when thesurgical system 10 pitches about a pitch axis of the dual-axis swiveljoint 404 as described below, the joints 404 a, 404 b can remained fixedsuch that motion of the slave assembly 100 and the master assembly 200is substantially the same. When the surgical system 10 remains fixedrelative to the pitch axis of the dual-axis swivel joint 404, the joints404 a, 404 b are free to pivot, thereby allowing a small amount ofsurging of the master assembly 200 and the slave assembly 100 relativeto one another.

The dual-axis swivel joint 404 of the coupling assembly 400 cangenerally be configured to provide two rotational degrees of freedom tothe surgical system 10, namely pitch and yaw. As shown in FIGS. 2 and10B, the dual-axis swivel joint 404 can be coupled between the middlestabilization member 408 and the floating frame 500. While the swiveljoint 404 can couple to any portion of the middle stabilization member408, in the illustrated embodiment, it is coupled to the member 408 at alocation just superior of the midpoint.

The dual-axis swivel joint 404 can have any orientation as desired. Insome embodiments, a first swivel joint 422 can be coupled to the middlestabilization member 408 in an orientation such that its centralrotational axis R1 is substantially perpendicular to a longitudinal axisL.A. of the middle stabilization member 408. The first swivel joint 422can allow the surgical system 10 to rotate about the first swivel jointaxis R1, i.e., to pitch about the surgical system's pitch axis(illustrated in FIG. 3). A second swivel joint 424 can have a centralrotational axis R2 oriented substantially perpendicular to the centralaxis R1 of the first swivel joint 422 and substantially parallel withthe longitudinal axis L.A. of the middle stabilization member 408. Thesecond swivel joint 424 can allow the surgical system 10 to rotate aboutthe second swivel joint axis R2, i.e., to yaw about the surgicalsystem's yaw axis (illustrated in FIG. 3). In this way, the dual-axisswivel joint 404 can provide the surgical system 10 with the tworotational degrees of freedom, i.e., the ability to pitch and to yaw.The third rotational degree of freedom, roll, is not provided by thiscoupling. Thus the surgical system 10 can be constrained in the thirdrotational degree of freedom such that the surgical system 10 cannotroll about its roll axis. As will be appreciated by those having skillin the art, a third swivel joint could be used if desired to provide thesurgical system 10 with the third rotational degree of freedom.

In some embodiments, the dual-axis swivel joint 404 can also define thepivot plane P, previously discussed with regard to FIGS. 4A and 4B. Thetwo axes R1 and R2 of the dual-axis swivel joint 404 can define a swivelplane S, as shown in FIGS. 10B and 10D. The pivot plane P can beparallel with the swivel plane S, with the additional requirement thatthe pivot plane P extend through the surgical access point A when theslave assembly 100 is disposed through an access point A in a tissuesurface. Thus, the orientation of the pivot plane P can change with theorientation of the swivel joint 404 as the surgical system 10 is movedso that it remains parallel with the swivel plane S. In an alternativeembodiment, the swivel plane S can also be defined by R2 and an axisparallel to R1 that extends through the pivot joint 404 a and/or thepivot joint 404 b. Thus, regardless of the orientation of the surgicalsystem 10, the swivel plane S can be defined by any one of the abovenoted parallel planes defined by the stabilization member 402.

As noted above, the pivot plane P, and thus the swivel plane S, also hasa relationship with the first plane F, defined by the longitudinal axesof the slave assembly 100 and the master assembly 200. In particular,the first plane F has a first axis F.A. that is parallel with the firstplane F and about which the surgical system 10 can yaw. In addition, thefirst plane F has a second axis S.A. that is transverse to the firstplane F. The first axis F.A. and the second axis S.A. define a planethat is parallel with the pivot plane P and the swivel plane S and/ordefines the pivot plane P. In some embodiments, the pivot plane P can beoriented perpendicularly to the first plane F.

The Floating Frame

In some embodiments, the floating frame 500 can be used with thesurgical system 10, as shown in FIGS. 11A and 11B. The floating frame500 can generally provide a counterbalance mechanism against the weightof the surgical system 10 so that the surgical system 10 “floats” abovea surface and/or a patient and is therefore easy to move. In addition,the floating frame 500 can provide the surgical system 10 with fulltranslational movement along all three coordinate axes such that thesystem 10 can heave, sway, and surge regardless of its rotationalorientation. In addition, the floating frame 500 can be fixedrotationally such that only the dual-axis swivel joint 404 discussedabove controls rotational motion of the surgical system 10.

In general, the floating frame 500 can be composed of various rods,brackets, and joints that extend between the dual-axis swivel joint 404and a fixed and/or stationary base 502 such as a hospital bed, floor,ceiling, operating table, etc. The particular floating frame 500described herein is only one embodiment, and the configuration and orderof the various rods, brackets, and joints is exemplary in nature only.Any frame capable of providing a counterbalance and three dimensionaltranslational movement for the surgical system 10 can be used. Further,any counterbalance system known in the art can be used to balance theweight of the surgical system 10.

As shown in FIGS. 11A and 11B, the floating frame can have a stationaryrod 504 that couples to a stationary base 502 such as the hospital bed,floor, ceiling, operating table, etc. The stationary rod 504 can begenerally oriented perpendicularly to the floor or other horizontalsurface and can be rigidly coupled to the stationary base 502 usingtypical methods known in the art including clamps, brackets, fasteners,etc. All movement of the floating frame 500 and the surgical system 10can be relative to the stationary rod 504. A cylindrical bearing 506 canbe disposed on the stationary rod 504 to provide the floating frame 500with 360 degrees of rotation about a central axis R.A. of the stationaryrod 504, as shown by arrow E in FIG. 11A. A pair of triangular brackets508 a, 508 b can couple to the cylindrical bearing 506, and twosubstantially rigid beams or rods 510, 512 can extend upward from thetriangular brackets 508 a, 508 b away from the stationary rod 504 andsubstantially in parallel with each other. The brackets 508 a, 508 b,rods 510, 512 and cylindrical bearing 506 can be coupled together usingany fastening mechanism known in the art including bolts, screws,adhesives, welding, etc. A lateral slide bracket 514 can couple the tworods 510, 512 together and provide a mechanism to adjust the lateraldistance between the rods 510, 512.

The two rods 510, 512 can couple into a pivotable joint mechanism 516that includes two sets of triangular brackets 520 a, 520 b, 522 a, 522 bjoined together by a dual rotation joint 518. The dual rotation joint518 allows the second set of brackets 522 a, 522 b, as well aseverything coupled to the brackets 522 a, 522 b, to rotate about thez-axis, as shown by arrow F in FIG. 11A. The dual rotation joint 518also allows the first set of brackets 520 a, 520 b, as well aseverything coupled to the brackets 520 a, 520 b, to rotate about they-axis, as indicated by arrow G in FIG. 11A. Two substantially rigidrods 524, 526 extend downward from the brackets 522 a, 522 b in asubstantially parallel orientation and terminate in a pair of brackets528 a,528 b. A connector rod 530 extends vertically downward from thebrackets 528 a,528 b and into the second swivel joint 424 of thedual-axis swivel joint 404 described above. The rods 524, 526, brackets520 a, 520 b, 522 a, 522 b, and dual rotation joint 518 can be coupledtogether using any fastening mechanism known in the art including bolts,screws, adhesives, welding, etc. The movement provided by the floatingframe 500 will be described in detail below.

In the illustrated embodiment, the counterbalance for the surgicalsystem 10 can be two coil springs 530 a, 530 b coupled to the floatingframe 500. The two coil springs 530 a, 530 b can couple on one end 531to the vertical most brackets 522 a, 522 b of the floating frame 500 byway of, for example, a hook and fastener connection, and can couple onan opposite end 533 to a mid-portion of the rods 524, 526. Since therods 524, 526 support the weight of the surgical system 10 through thedual-axis swivel joint 404 and the brackets 528 a, 528 b, the springs530 a, 530 b essentially “hold up” the weight of the surgical system 10.The position at which the springs 530 a, 530 b couple to the rods 524,526 can be adjusted to provide the proper balance to the surgical system10 such that the surgical system 10 is suspended and/or floats in theair. The springs 530 a, 530 b can provide a weightless feel to movementof the surgical system 10. As will be appreciated by those havingordinary skill in the art, any counterbalance known in the art can beused to balance the surgical system 10. For example, a hanging weightcan be used and/or another type of spring system can be used.

Use

There are many methods for using the above described surgical system 10and the floating frame 500, and any method steps discussed herein neednot be performed in a particular order. In use, the floating frame 500can provide the surgical system 10 with three translational degrees offreedom. Thus, in positioning the surgical system 10 in preparation foruse in a surgical procedure, for example, the surgical system 10 canheave, surge, and sway to be moved into position. In addition, thedual-axis swivel joint 404 provides the surgical system 10 with tworotational degrees of freedom as described above. The surgical system 10can thus also pitch and yaw as it is moved into position. As notedabove, in this embodiment the system 10 is limited from moving with thesixth degree of freedom, or third rotational degree of freedom, i.e.,rolling. In this way, and using the five degrees of freedom, thesurgical system 10 can be moved into position near a patient.

When the surgical system 10 is in position near a patient, as shown inFIG. 4, the slave arm 106, wrist 108, and end effector 102 can beinserted through a surgical access point A in a tissue surface, such asa trocar T or other access cannula, so that the end effector 102 isdisposed within a body cavity. Once the slave arm 106 is disposedthrough the access point A, the input tool 202 and the end effector 102are positioned on the same side of the pivot plane P that extendsperpendicularly to the longitudinal axis L.S. of the slave assembly 106and through the access point A. Movement of the master assembly 200 canthus result in mimicked movement of the slave assembly 100 to causepivoting and surging of the slave assembly 100 about the access point Aas needed to perform surgery.

While disposed through the access point A, the slave assembly 100, andthus the surgical assembly 10, is constrained. In particular, thesurgical assembly 10 can no longer heave or sway due its confinement inthe trocar T, thus removing two of the translational degrees of freedom.However, the surgical system 10 can still surge, pitch, and yaw whileconstrained by the access point A and thus it, as well as the endeffector 102, can have three degrees of freedom.

To perform a surgical procedure, the input tool 202 can be used tocontrol the end effector 102 within the body cavity. For example, theinput tool 202 and master arm 206 can be rotated around the longitudinalaxis L.M. of the master arm 206 to cause corresponding rotation of theslave arm 106 and end effector 102 about the longitudinal axis L.S. ofthe slave arm 106. This roll of the end effector 102 is an additional,fourth degree of freedom for the end effector 102. The input tool 202can also be pivoted or pitched relative to the master arm 206 to causecorresponding pitching of the end effector 102, resulting in anadditional, fifth degree of freedom for the end effector 102. However,this degree of freedom is redundant with the pitching of the surgicalsystem 10 provided by the dual-axis swivel joint 404, and thus the endeffector has four independent degrees of freedom.

In some embodiments, each of the jaws 234, 236 of the input tool 202 canbe opened and closed resulting in corresponding opening and closing ofeach of the jaw members 134, 136 of the end effector 102. This resultsin a yawing motion of the jaws 134, 136 relative to the end effector102, giving the jaws 134, 136 a sixth degree of freedom when added tothe pitch provided by the end effector 102. However, this degree offreedom is redundant with the yawing of the surgical system 10 providedby the dual-axis swivel joint 404, and thus the jaws 134, 136 also havefour independent degrees of freedom.

A surgical procedure can be performed using these various types ofmotion available to the end effector 102 and the jaws 134, 136. Once theprocedure is complete, the end effector 102, slave wrist 108, and slavearm 106 can be withdrawn from the surgical access point A. A personskilled in the art will appreciate that the above described embodimenthas applications in conventional endoscopic and open surgicalinstrumentation as well application in robotic-assisted surgery.

Surgical System II

Another embodiment of a surgical system 600 is illustrated in FIGS.12A-12C. The surgical system 600 can include identical master and slaveassemblies to the embodiment described above, and thus the detailsthereof will not be repeated. The components of the master and the slaveassemblies will be referred to with the same reference numbers as withthe surgical system 10, but with primes. The surgical system 600 canoptionally couple to the floating frame 500 through the dual-axis swiveljoint 404 as described above, and thus the floating frame 500 anddual-axis swivel joint 404 will also not be detailed again. It is to benoted, however, that because the surgical system 600 does not include astabilization member 404 that allows its master and slave assemblies200′, 100′ to surge slightly relative to one another, mimicked motion ofthe master and slave assemblies is generally only useful for relativelysmall angles of pitching and/or yawing.

FIG. 12A illustrates the surgical assembly 600, while FIG. 12Billustrates the slave side of the surgical system 600 and FIG. 12Cillustrates the master side of the surgical system 600. In thisembodiment, the pulley housings 210′, 110′ of the master and the slaveassemblies 200′, 100′ are coupled rigidly together within a housing 602.A bracket 620 extends between the master and slave housings 210′, 110′to secure them to the housing 602. The housing 602 can contain thepulley systems disposed within each of the pulley housings 210′, 110′ asdescribed above. However the mechanical linkage assembly described aboveis replaced with connector pulleys that transfer movement of the masterassembly 200′ to the slave assembly 100′. In particular, each of theslave pulleys 166 a′, 166 b′, 166 c′, 166 d′ (jointly “166′”) within theslave housing 110′ can be extended within the housing 602 as shown inFIG. 12B to have corresponding slave connector pulleys 604 a, 604 b, 604c, 604 d (jointly “604”). Each of the master pulleys 266 a′, 266 b′, 266c′, 266 d′ (jointly “266′”) can also be extended to have correspondingslave connector pulleys 606 a, 606 b, 606 c, 606 d (jointly “606”)similar to the master connector pulleys 604.

Each master connector pulley 606 and its corresponding slave connectorpulley 604 can be connected by a band 608 a, 608 b, 608 c, 608 d(jointly “608”) that transfers rotation between the two connectorpulleys 604, 606. Thus, for example, as the input tool 202′ is pitchedrelative to the master arm 206′, the corresponding master pulley 266 a′within the housing 602 rotates, causing rotation of its connector pulley606 a. Since the master connector pulley 606 a is connected by the band608 a to the slave connector pulley 606 a, the slave connector pulley606 a rotates to cause corresponding rotation of the slave pulley 166a′, which in turn causes the end effector 102′ to pitch relative to theslave arm 106′. The same applies to all movement of the input tool 202′and rotation thereof.

The housing 602 can take any suitable form in the art, but in theillustrated embodiment, it has an open construction composed of twoplanar portions 610, 612 connected by four rivets or fasteners 614 atthe corners. In addition, the pulleys 166′, 266′ and the connectorpulleys 604, 606 can be coupled together by any mechanism known in theart, including rotary fasteners, adhesives, welding, press fit, etc. Themovement available to the surgical system 600 is the same as for thesystem 10. When unconstrained by a trocar T, the surgical system 600 canhave five degrees of freedom. When constrained within a trocar T, thesurgical system 600 has three degrees of freedom and the end effector102′ has four independent degrees of freedom.

The devices disclosed herein can be designed to be disposed of after asingle use, or they can be designed to be used multiple times. In eithercase, however, the device can be reconditioned for reuse after at leastone use. Reconditioning can include any combination of the steps ofdisassembly of the device, followed by cleaning or replacement ofparticular pieces, and subsequent reassembly. In particular, the devicecan be disassembled, and any number of the particular pieces or parts ofthe device can be selectively replaced or removed in any combination. Byway of non-limiting example, the scraper and/or sorbent can be removed,cleaned, re-coated with a hydrophilic material, sterilized, and reused.Upon cleaning and/or replacement of particular parts, the device can bereassembled for subsequent use either at a reconditioning facility, orby a surgical team immediately prior to a surgical procedure. Thoseskilled in the art will appreciate that reconditioning of a device canutilize a variety of techniques for disassembly, cleaning/replacement,and reassembly. Use of such techniques, and the resulting reconditioneddevice, are all within the scope of the present application.

Preferably, the devices described herein will be processed beforesurgery. First, a new or used instrument is obtained and if necessarycleaned. The instrument can then be sterilized. In one sterilizationtechnique, the instrument is placed in a closed and sealed container,such as a plastic or TYVEK bag. The container and its contents are thenplaced in a field of radiation that can penetrate the container, such asgamma radiation, x-rays, or high-energy electrons. The radiation killsbacteria on the instrument and in the container. The sterilizedinstrument can then be stored in the sterile container. The sealedcontainer keeps the instrument sterile until it is opened in the medicalfacility.

One skilled in the art will appreciate further features and advantagesof the invention based on the above-described embodiments. Accordingly,the invention is not to be limited by what has been particularly shownand described, except as indicated by the appended claims. Allpublications and references cited herein are expressly incorporatedherein by reference in their entirety.

1-34. (canceled)
 35. A method for performing minimally invasive surgery,comprising: positioning a slave assembly through a surgical access pointin a tissue surface and into a body cavity such that an end effector ona forward end of the slave assembly is within the body cavity, the endeffector being disposed forward of a pivot plane that extends throughthe access point and has a first axis that is transverse to alongitudinal axis of the slave assembly and a second axis that isperpendicular to the longitudinal axis of the slave assembly about whichthe slave assembly yaws; and actuating an input tool coupled to aforward end of a master assembly disposed external to the body cavity tocause mimicked movement of the end effector within the body cavity, themaster assembly extending substantially parallel to the slave assemblyand the input tool being disposed forward of the pivot plane.
 36. Themethod of claim 35, further comprising rotating the input tool about alongitudinal axis of the master assembly to cause corresponding rotationof the end effector about the longitudinal axis of the slave assembly.37. The method of claim 35, further comprising surging the masterassembly to cause mimicked surging of the slave assembly through thesurgical access point.
 38. The method of claim 35, further comprisingmoving the master assembly to cause the slave assembly to pivot aboutthe surgical access point to define a conical volume within the bodycavity accessible by the end effector.
 39. The method of claim 35,wherein positioning a slave assembly through a surgical access pointcomprises moving a frame coupled to both the master assembly and theslave assembly that allows simultaneous movement of the master and slaveassemblies together in parallel with three translational degrees offreedom.
 40. The method of claim 39, further comprising moving adual-axis swivel joint coupled between the frame and the master andslave assemblies that allows simultaneous movement of the master andslave assemblies together in parallel with two rotational degrees offreedom, the dual-axis swivel joint defining a plane that is parallelwith the pivot plane.
 41. The method of claim 40, wherein the threetranslational degrees of freedom are surging, heaving, and swaying, andthe two rotational degrees of freedom are pitching, and yawing, andwherein the third rolling rotational degree of freedom is fixed.
 42. Themethod of claim 35, further comprising transferring mimicked movement ofthe input tool on the master assembly to the end effector on the slaveassembly through a mechanical linkage.
 43. The method of claim 42,wherein transferring mimicked movement through the mechanical linkageincludes transferring to the end effector rotation of the input toolabout a longitudinal axis of the master assembly and pivoting of theinput tool relative to the master assembly.
 44. The method of claim 42,wherein transferring mimicked movement through the mechanical linkageincludes transferring opening and closing of the input tool to effectsubstantially identical opening and closing of the end effector.
 45. Themethod of claim 35, wherein movement of the end effector is different inscale than actuation of the input tool.
 46. A method for performingminimally invasive surgery, comprising: inserting a slave assemblythrough a surgical access port and into a body cavity such that a slavewrist and an end effector coupled thereto are disposed within the bodycavity; and manipulating an input tool coupled to a master wrist of amaster assembly to transfer motion through a mechanical linkage assemblydirectly coupled between a master drive system and a slave drive systemto cause mimicked movement of the end effector, the master assemblybeing disposed outside of the body cavity and extending parallel to theslave assembly.
 47. The method of claim 46, further comprising rotatingthe input tool about a longitudinal axis of the master assembly to causecorresponding rotation of the end effector about a longitudinal axis ofthe slave assembly.
 48. The method of claim 46, further comprisingsurging the master assembly to cause mimicked surging of the slaveassembly through the surgical access port.
 49. The method of claim 46,wherein manipulating the input tool moves at least one of a plurality ofcables of the master drive system, and wherein the master drive systemincludes a pulley system.
 50. The method of claim 46, wherein insertinga slave assembly through a surgical access port comprises moving a framecoupled to both the master assembly and the slave assembly.
 51. Themethod of claim 50, wherein moving the frame causes simultaneousmovement of the master and slave assemblies together in parallel withthree degrees of translational freedom.
 52. The method of claim 51,wherein the three degrees of freedom are surging, heaving, and swaying.53. The method of claim 46, wherein rotating the input tool on themaster assembly about a longitudinal axis of the master assembly causesrotation of a first drive rod of the mechanical linkage assembly toeffect corresponding rotation of the end effector on the slave assembly.54. The method of claim 53, wherein pivoting the input tool on themaster assembly relative to the longitudinal axis of the master assemblycauses rotation of a second drive rod of the mechanical linkage assemblyto effect corresponding pivoting of the end effector of the slaveassembly.
 55. The method of claim 54, wherein opening and closing of theinput tool of the master assembly rotates third and fourth drive rods ofthe mechanical linkage assembly to effect corresponding opening andclosing of the end effector of the slave assembly.
 56. The method ofclaim 46, wherein moving the input tool results in scaled movement ofthe end effector.